The present invention relates to an optical coupling module for optically
coupling an optical fiber with an optical waveguide, and a method of
fabricating the optical coupling module. In an optical coupling module
for optically coupling an optical network with a planar lightwave circuit
(PLC), an etched groove for disposition of the optical fiber and an
etched groove for mounting of the optical waveguide are exposed using a
mask having mask patterns that are aligned with each other, and then
anisotropically etched. By doing so, the two grooves can be precisely
aligned with each other at one time, compared with a conventional method
in which an exposure process is carried out two or more times.
Accordingly, an inexpensive structure having high optical coupling
efficiency upon manual alignment can be obtained. In addition, since a
tapered structure in which an inlet is larger than a body is employed in
the optical waveguide, tolerance in vertical and horizontal alignment
upon manual alignment can be broaden, resulting in improvement of optical
coupling efficiency and facilitation of manual alignment. Furthermore, by
utilizing a thick insulation film on the substrate or a thick insulation
film of the optical waveguide itself as a board, a structure for allowing
assembly into and application to a high-frequency electric-optical
circuit can be obtained.